Stochastic Simulation of the Impact of Commodity Price Variation onMastitis Costs

摘要

Mastitis is one of the most expensive diseases in the dairy industry (Seegers et al., 2003). The National Mastitis Council estimated mastitis costs at $184.40 per cow per lactation in 1996. Literature shows clinical mastitis costs range from $3.64 to$366.45 per clinical case (Halasa et al., 2007).The objective of this research was to evaluate the impact of varying commodity prices and cow factors on 2012 mastitis costs. This dynamic, stochastic, and farm-level model was first described by Bewley etal., (2010) and constructed using Microsoft~R Excel (Microsoft, Seattle, WA). The @Risk Monte Carlo simulation add-in (Palisade Corp., Ithaca, NY) was used to predict commodity prices and calculate mastitis costs and associated sensitivities. Baseline milk, replacement cow, slaughter, corn, soybean, alfalfa prices were established using historic USD A NASS prices from 1970 to 2011. The stochastically predicted commodity prices were modeled using FAPRI (Food and Agricultural Policy Research Institution,Columbia, MO) estimates for 2012 to 2021. Feed cost was calculated using corn, soybean, and alfalfa and the USDA feed cost formula. A 162 Holstein cow US dairy farm, with default herd parameters established using DairyMetrics (Dairy Records Management Systems; Raleigh, NC) and published literature was simulated through 5000 iterations.